Super Mario Bros. Wonder will feature talking flowers in every course that make all sorts of amusing comments and liven up the whole experience. If you don't like the idea of this though, it seems you'll be able to silence them.
As highlighted by Nintendo Everything, a screenshot (and rough translation) on Nintendo's Japanese website suggests players will be able to disable flower audio in a particular menu. It seems you'll be able to change the language in here as well:
While Nintendo encourages players to keep the flower audio on, we can imagine if you've played through a certain level a million times, the constant chatter may get a bit irritating for some - so this might be a handy option. Or, if you just want a more traditional-sounding Mario game, this could also be a good reason to silence the flowers.